Hacking 3DS Video Metadata

[drfsupercenter]

So we have a video converter, which is great and everything. But I'm sure you all have discovered that it makes your videos show that they were taken in 1900.

Looking at an actual video from my 3DS, there is a RIFF header that uses what looks like EXIF data with some dates in it.

.00dc´...ÿØÿà..AVI1..........ÿá.øExif..MM.*.................z...........„...........’...........š.(...........1.........¢.2.........¨............‡i.........¼....Nintendo..Nintendo 3DS.....H.......H....00204.2011:12:31 16:07:37...........0220...........:...........N‘...........’|.....R...b .......0100 ........... ..........à ..........ð ..........´....2011:12:31 16:07:37.2011:12:31 16:07:[email protected]....Éï‘.............ßk‡.............Y.¬Á....€.........................R98.........0100...........Þ....JPEG Exif Ver 2.2.ÿÀ....ð.à..".......ÿÛ.„................ .....'... .)10.)-,3:J>36F7,-@WAFLNRSR2>ZaZP`JQRO.......&..&O5-5OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOÿÄ.¢.

There's a bunch of these followed by the actual video data.

So I tried just replacing the generic header with the same header as my original video, and it wouldn't open on my computer anymore. So there's obviously more to this than I'm seeing.

It doesn't really look encrypted, the fact I can see "Nintendo 3DS" and a date in there at all would suggest that it isn't. But is the length of the file also stored in there? That might be what's screwing it up. The annoying thing is that EXIF editors won't allow me to open the AVI files because they aren't JPEG images. It would just be nice if we could make the videos show as today's date opposed to 1900, since I have like 500 images on my 3DS and it's a major pain in the butt to keep going back to the start for each video.

 

[ferofax]

I actually prefer the date 1/1/1900 over any other.

This way, all my non-3DS data is always at the start of the album--not in some obscure date in the middle or anywhere else, hidden among the thousands of photos (and a few videos) i currently have.

 

[drfsupercenter]

Couldn't one do the reverse then and set them all to like 2050?

Regardless, I would like to know if it's possible to inject the metadata.

I've been playing with Exif viewers and editors for several hours, and I give up. This is stupid, none of them can find any metadata in the 3DS AVIs at all, despite it being right there in plain text in a hex editor. The question becomes, what part do I need to copy to make it work? If you copy the whole header it won't work, probably due to a mismatch in the number of frames/framerate/bitrate as all of that is stored in the header too.

 

[spinal_cord]

If the avi header allows you to change the offset of the video streams within the file, just find out where the start of a 'real' 3ds video is, adjust the offset in a converted video then implant the data in the same place as 'real' 3ds video.

On the other hand, have you tried just changing the information in a video you recorded yourself to make it appear in a different point in the list? I did, it didn't work...

 

[elisherer]

These dates are the dates from the exif tag of the jpeg inside the mjpg stream...i don't think the 3ds recognizes the date by these tags..

But, it might be inside the MakerNote exif tag. Nintendo uses a special makernote. you can read about it here http://3dbrew.org/wiki/MPO

 

[drfsupercenter]

On the other hand, have you tried just changing the information in a video you recorded yourself to make it appear in a different point in the list? I did, it didn't work...

Yep. It worked fine. You have to replace *all* the dates (there are like 10 of them) with a different date. I made a video last night so it was 01/03/12 and changed it to 01/02/12 and it actually showed up fine as both dates (since I copied the file rather than overwriting it).

 

[drfsupercenter]

As for the EXIF structure in the MPO files, that doesn't really explain how to add it in hex. I know what Exif headers are, the problem is that nothing supports them for AVI, and there's a bunch of jibberish data in there between the meaningful stuff, not sure if that's encrypted or if it's just jibberish.